But Sizzlers, which lists its first ingredient as "meat (including pork)" was found to contain cattle and chicken meat as well as pork.

A spokesman for Goodman Fielder, which manufactures Sizzlers, said the product complies with the strict regulatory food standards on labelling, specifically the Australian New Zealand Food Standards Code.

"In addition to this, we voluntarily elaborate on the pork content in Sizzlers to ensure persons with specific religious considerations are aware that pork is a component of the product."

He said Sizzlers do not contain offal.

Manufacturers do not need to specify which meat types are in a product, as long as they identify it as "meat", without any further details, the Ministry of Primary Industries said.

However, if a product with only "meat" listed in its ingredients was found to contain a meat not commonly eaten in New Zealand - such as horse - it could be in breach of the Fair Trading Act.

Spokesman for the Ministry of Business, Innovation and Employment, Alastair Stewart, said the claim of a breach of the act could be compounded if, for example, the "meat" product carried images of cows grazing.

"It's an absolutely appalling loophole ... everyone wants to know what they're eating. Manufacturers shouldn't be trying to hide what is in their food, they should be absolutely honest with consumers."

Ms Kedgley said it should be "absolutely compulsory" that manufacturers be forced to include on their labels exactly what was in their products.

It was comforting, she said, that so few products sold in New Zealand hid behind the "meat loophole", but that it still shouldn't exist.

The horsemeat scandal in Europe has lifted the lid on industry labelling regulations and has helped inform consumers about what really goes into their food, Ms Kedgley said.